A vehicle with an engine mounted thereon, which is driven by the engine, is in wide use today. Examples of the vehicle include an automobile and a straddled vehicle. In such a vehicle, generally, a liquid fuel such as gasoline or gas oil is used as an engine fuel.
Refueling the vehicle with a liquid fuel is performed in a gas station, for example. The gas station is widespread in these days. A gas-station network is constructed over a wide range. It is therefore relatively easy for a user to go to a gas station for refueling a vehicle with a liquid fuel in case of deficiency of the liquid fuel. In general, refueling the vehicle with a liquid fuel at a gas station is completed in a few minutes. Thus, the refueling the vehicle with a liquid fuel is easy and convenient for a user. From this point of view, a vehicle (hereinafter also referred to as an engine vehicle) provided with an engine that is operated with a liquid fuel is user-friendly.
As for maintenance of the engine, on the other hand, there are many maintenance items. Performing a maintenance operation on the engine is more complicated than refueling with the liquid fuel. Therefore, the maintenance of the engine takes a relatively long time.
Patent Literature 1 (PTL1) (identified further on) discloses a scooter-type motorcycle. The scooter-type motorcycle of Patent Literature 1 has a plurality of maintenance holes formed in a part of a vehicle body. This configuration of the scooter-type motorcycle of Patent Literature 1 makes it easy to perform maintenance of the engine and therearound.